Study on primal CO gas generation and emission of coal seam

Zhu, Huangqiu; Chang, Mingran; Wang, Haiyan

doi:10.1016/j.ijmst.2017.06.002

Cited by 36 publications

(9 citation statements)

References 29 publications

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“…www.nature.com/scientificreports/ accumulation of fire gases in the pore structure of coal may result in lowering the value of their concentrations in gaseous samples collected at stations of early detection of mine fires. Numerous studies of the process of selfignition of coal have shown that with the development of a fire, characteristic gases such as carbon monoxide, carbon dioxide, hydrogen, propylene and ethylene begin to appear in the mine atmosphere 59,60 . The concentration of these gases rises up with the increases in coal temperature.…”

Section: Resultsmentioning

confidence: 99%

Effect of porous structure of coal on propylene adsorption from gas mixtures

Wojtacha‐Rychter

Howaniec

Smoliński

2020

Sci Rep

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This paper addresses the issue of the sorption process on coal concerning propylene released from the source of coal heating in the deposit. In this study, the interaction between Polish coals and propylene molecules, as well as three other hydrocarbons (ethylene, ethane, and propane) with the application of a fixed-bed column, was investigated. The experimental results show that propylene adsorption was measurable under the experimental conditions. The differences in the amount of adsorbed propylene were predominately caused by various gas diffusion rates within the pore network associated with the molecular sieving effect. According to the experimental results, the influence of mesopores on propylene adsorption was significantly stronger than the share of micropores of the explored coals. The column tests demonstrated that the largest amount of propylene was adsorbed by coal with the highest value of pore diameter (6.48 nm) determined by nitrogen adsorption at 77 K. Under the experimental conditions, the influence of other hydrocarbons and a surface area on the quantity of the adsorbed gas was unnoticeable. This study provides an understanding of the behavior of some of the fire gases during the flow of the mixture through a heterogeneous structure of coal in the mine environment. The sorption of gases from multi-component mixture released during the selfheating of coal on carbon materials such as bituminous and lignite coals is poorly understood which provides the rationale for the topic of this work.

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Section: Resultsmentioning

confidence: 99%

Effect of porous structure of coal on propylene adsorption from gas mixtures

Wojtacha‐Rychter

Howaniec

Smoliński

2020

Sci Rep

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“…Its production exhibits a clear increasing trend with increasing oxidation temperature. Therefore, carbon monoxide CO is considered an index gas for spontaneous coal combustion 22–25 . By monitoring changes in CO concentration in real time, the coal oxidation process can be directly reflected to allow for immediate measures that curb the rise in temperature 26–29 .…”

Section: Resultsmentioning

confidence: 99%

Effect of coalbed methane airflow with optimum action concentration on coal oxidation under low temperatures

Yang

et al. 2020

Asia-Pacific J Chem Eng

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To explore the effect of coalbed methane (CBM) airflow on coal oxidation under low temperatures, an experimental apparatus was developed and applied to simulate coal oxidation under different oxidizing atmospheres. The formation of carbon monoxide CO, the index gas, in CBM airflow was analyzed to obtain the optimum concentration of CH4 that exerted the strongest influence on coal oxidation. Then, a comparison experiment was performed on coal oxidation in dry air and in CH4 at the optimum concentration by using electron spin resonance (ESR) and Fourier transform infrared (FTIR) technology. The results suggest that 25% of CH4 has the strongest effect on coal oxidation at low temperatures. The free radical concentration (Ng) in coal increases with temperature in both dry air and 25% CH4. At this concentration, CH4 can inhibit the reactivity of coal substantially while raising the excitation temperature. The oxidation of aliphatic hydrocarbons is severely inhibited by 25% CH4, which reduces its consumption rate and abates its decrement in the initial phase. Although 25% CH4 restricts the consumption of –OH and –COOH in oxidation, it promotes the formation of –C–O.

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“…States, India, and Australia, 4,5 which not only wastes energy, but also pollutes the environment, and even leads to land subsidence and human casualties. [6][7][8][9] Coal spontaneous combustion is a complex physical and chemical process, 10 which although is characterized by the accumulation of heat 11,12 and the production of index gas, 13,14 is essentially a chemical reaction between active functional groups. [15][16][17][18][19][20] Research on the evolution of functional groups during the heating of coal helps us form a deeper understanding of the mechanisms at work during coal spontaneous combustion, which in turn, can provide a theoretical basis for the prevention and control of this disaster.…”

Section: Introductionmentioning

confidence: 99%

The evolution law of functional groups during the heating of coal in oxygen and oxygen‐free atmospheres

et al. 2021

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There is a change in both the quantity and type of functional groups due to the fact that they become oxidized and pyrolyzed during the spontaneous coal combustion process. In order to study the oxidation and pyrolysis mechanisms that are at play during the evolution of these functional groups, in situ Fourier transform infrared (FTIR) spectroscopy was employed to test the real-time evolution of these functional groups in both air and argon atmospheres. The differences found between functional groups when under an oxygen oxygen-free environment were analyzed. The results show that when the temperature exceeds 200°C, the changes in functional groups steadily increase and that regardless of whether the atmosphere is made up of argon or air, the oxygen-containing functional groups change significantly. In this situation, −OH, −CH 3 , and −CH 2 -are important reactants in the whole heating process; −COOH and −C=O are reactants during the low temperature oxidation stage, but when reaching the high temperature stage, they become the products; C-O-C and C=C is a stable reaction product. During the coal spontaneous combustion process, oxidation and pyrolysis work as two coupling reactions: The heat released by the oxidation reaction pyrolyzes the macromolecular structure and coal-oxygen complexes, while a large number of active groups are produced during pyrolysis, which then provides the reactants for the oxidation reaction. These results reveal the changes that functional groups go through during the process of oxidation and pyrolysis, and provide a theoretical basis for the development of efficient fire-fighting materials.

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Study on primal CO gas generation and emission of coal seam

Cited by 36 publications

References 29 publications

Effect of porous structure of coal on propylene adsorption from gas mixtures

Effect of porous structure of coal on propylene adsorption from gas mixtures

Effect of coalbed methane airflow with optimum action concentration on coal oxidation under low temperatures

The evolution law of functional groups during the heating of coal in oxygen and oxygen‐free atmospheres

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